Chuck unit particularly adapted for stem making machines



May 30, 1944. J. EHRET. JR

CHUCK UNIT PARTICULARLY ADAPTED FOR STEM MAKING MACHINES Filed March 29 INVENTOR J. EHREL' JR A T TORNEY elements.

Patented May 30, 1944 UNITED STATES' PATENT. 'ortica 'CUCK` UNIT PARTICULARLY ADAPTED FOR' STEM MAKING MACHINES i John E1n-et, Jr., Trenton, N. J., assignmto weltern Electric Compannlncorporated, New York, N. Y., a corporation of New York Application March 29, 1941, serial No. 335,813 t 6 Claims.

This invention relates to chuck units vparticularly adapted i'or stem making machines.

'I'he term stem defines the glass members of incandescent lamps, vacuum tubes, 'photoelectric cells or the like inwhich are held the supporting wires for the laments| grids, and other electrical The number of supporting wires and their relative spacing, in addition to the size and contour of the finished article, determine the size and'shape of the glass portion of tlie stem structure.

An object of the invention is to provide highly eiilcient chuck umts for use in stem making machines and particularly adapted for dished glass stems.

With this and other objects in view, the invention comprises a chuck unit adapted to singly receive dished glass members and supporting K wires for the making ql stems, the chuck unit including holding elements to removably hold the glass members against displacement and a plunger reciprocally relative to the glass members during the application of heat thereto in fusing the glass about the wires `to maintain the shape of the glass members.

Other objects and advantages will be apparent from the following detailed description when taken in conjunction with the accompanying drawing, wherein Fig. 1 is a vertical sectional view of one of the chuck units of the machine;

Fig. 2 is a top plan view of the chuck unit taken substantially along the line 2--2 of Fig. 1 with g portions thereof broken away;

Fig. 3 is a side elevational view of the chuck unit shown in open position and illustrating the -associated cams, and

Fig. 4 is a schematic top plan view of a portion of the stem making machine. t

Referring now to the drawing, attention is iirst directed to Fig. 1, which illustrates a turret I0 with one of the chuck umts indicated generally at II. It will beapparent, by viewing Fig. 4,

' that inthe present embodiment there are eight ing adjustable stop nuts 2| and a cam engaging nut 22. The nut 22 is positioned to ride upon a circular cam 24 extending concentrically about the axis of the machine beneath the clutch units as illustrated in Fig. 4. The cam 24 is formed with a plurality of high portions 25 disposed at denite spaced positions to cause reciprocation of the plunger I9 at definite intervals during each cycle of the machine operation.

A head portion 23v is formed integral with the upper end of the plunger I9 and is of a some-v what semi-spherical contour. The head portion 28 is movably disposed in a support 33, which is hollowed at 3| to receive the head portionand to receive also an annular member 32, which is held in place and secured to the support by a set screw 33. The annular member 32 has a plurality of vertical apertures 34 disposed therein at equally spaced positions, as illustrated in Fig. 2, to receive tubular members 35, the latter projecting upwardly from the annular member to receive supporting wires 36 of` stems to be formed.

Tubular members 35 rest upon a surface 3l of the support 311,` this surface also serving as a stop and a support for' the wires 36. As illustrated in Figs. 1 and 2, the head portion 23 has a series of equally spaced notches 38.1n its periphery for the tubular members 35 to allow the head portion to straddle the tubular members and move relative thereto. By viewing Fig. 1, it will be observed that the support 30 has a reduced portion 39 projecting into an enlarged portion of the opening I8 in the body member I2, concentric with the plunger I9, Vwhere a set screw 43 secures this portion with the support to the body member I2. Attention is now directed to the upper portion of the support 30, which is recessed as at 42 to receive a dished glass member 43, the latter ,to become a part of a stem assembly with the supporting wires 36.

Means is provided to hold the glass member 43 in the vrecess of the support during the forming of the stem and to release the glass member after the forming operation has been completed. This holding means consists of a plurality of holding members in the form of pivoted arms 45 disposed at spaced positions about the body I2. In the present instance, there are four arms each pivoted at its lower end, as at 45, to an element 41, the latter being slidably disposed upon the body andnotched, as at 48, to receive the pivots 45. A key 49, carried by the body I2 and receivable in an elongate slot -50 in the elemht 41., serves to allow reciprocation of the element 'but to hold the element against rotation relativeto the body.

A spring 53, disposed concentric with the body i2, is positioned between the support 30 and the element 41 to normally urge the element downwardly. The upper ends of the arms 45 are secured to article engaging members 55 of the contour illustrated in Figs. 1 and 2. These members have arcuate portions 55 conforming somewhat to the contour of the glass member 43 to project over a flanged portion 51 of the glass member to hold the glass member in recess 42. The arms 45 are also provided with cam grooves 40 of the contour illustrated in Fig. r and in which are disposed pins 3| carried by projections of the support 30 to control movement of the arms during vertical movement of the element 41. 'I'he vertical movement loi the element 41 is caused by a cam. 63 disposed concentric with the cam 24, as illustrated in Figs. 3 and 4. A cam'engaging member 65, in the form of a pin carrigd by the element 41, rides upon the cam 83 and, when moving upon a high portion 66 of the cam, the element 41 will be moved upwardly to cause actuation of the arms 45. i

Attention is now directed to the lower portion of Fig. 1 and to Fig. 4, where a gear 10 is mounted upo'n the body i2 beneath the turret l0 and xed to the body by the alii of a set screw 1l. 'I'he gear; is provided with teeth 12 oi' any desired structure and positioned to be engaged by a resilient rotatable driving member 13, winch, in the present instance, is a rubber Wheel. Referring now to Fig. 4, attention is directed to the fact that there are five rubber wheels 13 disposed at spaced positions adjacent five stations to be successively assumed by each chuck unit during the travel of the latter intermittently through each cycle of the machine. The wheels 13 are driven through the aid of a common belt 14 connecting all of the wheels and their rotatable shafts with a driving shaft 15. 'I'he driving shaft 15 is connected operatively with a power means, not shown, to cause rotation of the chuck units during the rest periods of the turret.

During the operation of the machine, the turret III is rotated counterclockwise, Fig. 4, intermittently moving the chuck units from station to station. .At stations indicated at 30 and 8l, the arms 45 are in the open positions shown in Fig. 3 for the positioning ofa glass member 43 in the recess 42 of the support 30 and the positioning of the supporting wires 35 in their tubular members 34. During this assembly of parts, the wires are fed through apertures previously formed in the glass member 43, which apertures align with the tubular members '34. At a station indicated at 32, the pin 55 rides downwardly oiI of the high portion 55 of the cam 53, allowing the force of the spring 53, together with the force of gravity, to move the element 41 downwardly, movingwith it the arms 45 and their members 55. During the downward movement of the arms 45, the cams 50 and their respective pins 6| cause the arms to move inwardly to position the arcuate portions 55 of the `members 55 over and in gripping engagement with the ilange of the glass member 43, In this manner, the glass member is held in place during 'the iive subsequent stations 83, 84, 35, 35 and 81. While the chuck units are located at the lastmentioned stations, their gears 10 are disposed in engagement with the adjacent wheels- 13v and, through this engagement, the body members, that is, the chuck units, in general, are caused to rotate.l At each of these stations where the chuck units are rotated, heat is applied to the glass members 43 by suitable means, such as gas jets 90. illustrated `in Fig. 1. Therefore, at the stations where the chuck units are rotated, the glass members 43 are heated to soften the glass and seal vthe wires. thereinl The application oi' heat to glass members 43.0! the contour illustrated softens the members, and without suitable means to prevent it, the central portions of these members will sag and thus become deformed. This condition is eliminated through the aid of thel plunger I9 and its head portion 23. At definite intervals during the application of heat to the glassrmember of each unit, the plunger i9 thereof is reclprocated through .the association of the nut 22 with the high portions 25 of the cam 24 to repeatedly move the head portion- 23 to move the central portion of the glass member upwardly to its normal position. 'I'his operation oi' the plunger and its head portion takes place after each station 33, 34,35, 36 and 31, the operation continuing after the latter station until the glass member has had suiiicient time to cool and again solidify. In this manner, the contour of the glss member is maintained.

After each chuck unit leaves the position of the station 81, the pin 55 thereof is positioned to ride upon Ithe high portion 55 of the cam 43, moving the element 41' upwardly against the force of the spring 53 and through the cams 30 and their pins 5|' move the portions 55 ilrst upwardly, free of the flanges 51, and then outwardly to the positions shown in Fig. 3, freeing the completed stem for removal by the operator.

.1. The embodiment of the invention herein disclosed is merely illustrative and may be widely modified and departed from in many ways without departing from the spirit and scope of the invention as pointed out in and limited solely by the appended claims.

What is claimed is: v

l. A chuck unit for a stem making machine comprising a body having a. central opening, an annular element secured to the body within the opening for supporting a plurality of wires, means for removably holding a glass member so that the wires extend through apertures therein, a reciprocable plunger 4poistioned within the annular element, and means for reciprocating the plunger to cause it to engage the under surface of the glass member at predetermined times.

2. A chuck unit for a stem making machine comprising a supporting -means for holding in predetermined relationship a dish-shaped glass member and a plurality of wires extending through apertures `in the dish lportion of the glass, a plunger positioned beneath the dish portion of the glass and having a head with openings through which the wires pass, said plunger being positioned. centrally of the supporting means, and mea for moving the plunger. to cause its head to engage ,the under surface of the dish portion of the glass to maintain its contour during the time it issoftened by heat in a sealing-in operation.

3. A chuck unit for a stem making machine comprising a support for holding a plurality of wires within an opening thereof, means for removably clamping a glassmember on the support so that each wire protrudes through an individual aperture in the glass member, a shaping head positioned within the opening of the support, and means for moving vthe head to cause it to engage the under surface of the glass inember to maintain its original contour during the fusing of the glass to the wires.

' 4. A chuck unit for a stem making machine' comprising a support having a central opening, means for holding the rim of a dished glass member on.the support over the opening. means within the opening of the support for holding wires so that they project through apertures in the dished portion of the glass member, means positioned within the central opening of the support and movable into engagement with the underside of the glass member to maintain the original contour of the member when heat is used to seal the glass to the wires, and means for moving the holding means away from the support to free the glass member and the wires secured thereto.

5. A chuck unit for a stem making machine comprising a body having a central opening, means for holding a plurality of wires in predetermined positions in said opening, a seat provided in the body above the central opening for supporting a dished glass member over the opening so that the wires extend through apertures in the glass member, means for holding the glass 2u toward and away from the free the glass member and the wires sealed thereto, and means for causing lateral movement of the holding means away from the body during the upward movement thereof.

6. A chuck unit for a stem making machinel comprising a hollow body having a seat formed thereon to support a dished'glass member over an open end ot the body, tubes disposed in the body for supporting wires to be sealed in the glass member, a plurality of holding elements for holding the glass member in the seat, arms for i supporting the holding elements, and a ring secured to the arms and movable axially of the body to move the arms and the holding elements glass member.

JOHN EHRET, Jn. 

